This invention relates to a process for producing ether and ester compounds which have a difluoromethyl group, and also to novel ether compounds containing a difluoromethyl group which are obtainable according to the process of the invention.
Ether and ester compounds which have a difluoromethyl group (CF.sub.2 H--), can be used in combination with surface-active compounds, e.g. phosphoric acid esters, for removing water from surfaces of objects. In combination with agents which have a lubricating effect, they can be used as lubricants. Furthermore, difluoromethyl ethers, e.g. CHF.sub.2 OC.sub.6 H.sub.5, CHF.sub.2 OCH.sub.2 CF.sub.3, CH.sub.3 CH.sub.2 OCF.sub.2 H or CH.sub.3 OCF.sub.2 H, can be used as substitutes for fluorochlorohydrocarbons.
Difluoromethyl esters are intermediate products and can be used as solvents.
The production by fluorination of corresponding dichloromethyl ethers is very difficult due to the low reactivity of these compounds with respect to chlorine/fluorine exchange (in which a bond breakage may also take place on the oxygen atom).
The production of difluoromethyl phenyl ethers from chloroform, potassium fluoride and phenol, which is described by B. R. Langlois in Tetrahedron Letters 32 (1991), pages 3691-3694, is successful, but only with a low yield.
The production of difluoromethyl ethers, e.g. from enfluorane or isofluorane, takes place by reacting the unstable starting compound fluorosulphonyl difluoroacetate and alcohols, see Chen and Wu., J. Fluorine Chem. 44 (1989), pages 433 to 440. The authors mention that it is also possible to produce difluoromethyl ethers from difluoroaziridine and alcohol in glass ampoules. Due to the difficulty of supplying aziridine, the application of this method is limited.